Exotic baryons and monopole excitations in a chiral soliton model

Abstract

We compute the spectra of exotic pentaquarks and monopole excitations of the low-lying

Dynamics of pentaquarks in constituent quark models: recent developments

“…The symmetry [4] O implies that there is no orbital excitation and the parity of the pentaquark is negative, i. e. the same as the intrinsic parity of the antiquark. But if one quark is excited to the p-shell the parity becomes positive and the lowest symmetry allowed for the orbital part of the wave function is [31] [4] F S in its lowest state, which has I = 0 and S = 0. Although this state contains one unit of orbital excitation the attraction brought by the FS interaction is so strong that it overcomes the excess of kinetic energy and generates a positive parity state below the negative parity one [10].…”

“…As above, this implies an excess of kinetic energy due to an extra unit of orbital angular momentum. Then, according to the Pauli principle, the lowest symmetry of the wave function in the relevant degrees of freedom is [31] CS . This symmetry brings less attraction than [4] F S in the FS model, which is insufficient to overcome the excess of kinetic energy.…”

“…It was found that this can reduce the size of the widths of the antidecuplet members without much affecting the masses. However, another chiral soliton study [31], based on an "exact" treatment (not only the first order) of SU(3) F breaking advocates large 8 + 10 mixing from the mass analysis. Thus the representation mixing seems to remain a controversial problem in the chiral soliton model.…”

Bound-state versus collective-coordinate approaches in chiral soliton models and the width of the Θpentaquark

“…For N C = 3 the Θ * pentaquark is expected to be roughly 100MeV heavier than Θ + [39,59]. The Yukawa interactions of the RVA, eq.…”

Strangeness observables and pentaquarks

“…like the old predictions of the soliton model [86,17] and expected by others e.g. new calculations of the soliton model [79,87]. Furthermore, lattice calculations give very different results to the questions if pentaquarks exist and which mass and parity they have.…”